These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Internet Backdraft: There used to be endless wank over the so-called "genders" of the angels, whether or not Tokyopop translated them as girls due to homophobia or if even in Japanese the angels were meant to be male and the manga meant to be shounen-ai themes.
The Woobie: Kohaku, particularly in the later volumes after her powers are taken away and Shuichiro dies.